The whiterot fungus Trametes versicolor decolorized Amaranth. The hypothesis
that the carbon structure of Amaranth was broken down in smaller mass fragments
was investigated analyzing the products of decoloration. FTIR spectroscopy, ion
chromatography, sulfite and ammonia analysis were used to compare the culture
filtrate before dye addition, with the pure dye, the culture filtrate after dye
addition, and the culture filtrate during the treatment. The hypothesis of
polymerization of the decoloration products was tested by spectrophotometric
analysis of dialysates of the pure dye, the culture filtrate before dye addition, and
the culture filtrates after dye addition and decoloration. FTIR showed that the
signals typical for the azo group disappeared after decoloration, while new peaks
appeared that were characteristic of substituted naphthalenic or benzenic
compounds. Ion chromatography showed that the level of sulfate in the treatment
increased when compared with the level of the sulfate in control, suggesting that
the sulfonic groups were being stripped from Amaranth’s structure and
metabolized to sulfate. Sulfite measurements for the treatment and controls
showed no significant difference, and were well below the saturation concentration
for sulfite in water, confirming that the medium was aerobic. Ammonia
concentration did not change with the decoloration. Absorbance scans after
dialysis of decolorized samples showed no new peaks, suggesting that the
decoloration products were not polymerized